Don't get me wrong but I find this advise rather outdated. I mean, sure, playing a TAG game is - most of the times - the way to go, but that doesn't mean "only go in with the top hands".
You should have a set range for specific situations (e.g. position; effective stack; action up to you; players left to act; etc.).
Opening 7s8s from the BU, when the action is folded to you, is not exactly going in with a "top hand" but it certainly would be a very advisable play, much better than folding or simply limping in.
On the other hand, GII after you've raised QQ, was met by a reraise and an all in shove for 300BB effective, is not a really good idea, even though QQ is a premium hand.
Also, I find it rather unuseful to categorize people as TAG/LAG. I find it better to understand their ranges (and our perceived ranges to them) and notice how these ranges play and how they connect to specific boards. If you simply think "he's LAG, I'll play TAG", you'd miss out on plenty of information you could use to your advantage.
For instance, if a player is raising 60% of his hands preflop, you can assume he's playing 22+, A2+, K2+, Q3+, J7+, T8+, 98+, suited connectors, two gapped suited connectors, and most suited combinations. You can reraise to isolate him with a range that includes 22+, suited connectors and all broadways and still have close to 60% equity against his range.
With this, you can actually even further pin down his range, depending on his action. He might be a player that would: reraise JJ+, AJs+, KQs, AQ+,; flat 22-TT and suited connectors; and fold all rags. So now you go into the flop with more information to better navigate your play depending on the board's texture.
So say we have AhTh in the BU. Villain is HJ, effective stack is 150BB. Action folds to the Villain, who raises to a standard 3BB. We have a nice hand with 62.25% equity against Villain's range.
We put in a raise, making it 11BB to go. Action folds back to Villain who simply calls.
Flop comes KsQd3h. So we have a backdoor flush draw, a gutshot and a flop that hits our range way better than it hits Villain's range. The only hands that are in his range that could realistically hit that flop are KQo, QJs, 33 and maybe TJ for a double-ended.
If villain bets, we can call and reassess. If villain checks, we can either bet and take the pot down (dead money) or check, since we fold most of his range we already have beat, we only get calls from QJ and TJ and probably get reraised by KQ and 33.
Anyway, that was just an illustration of how thinking in ranges can work to your advantage.
Thanks for your input.
Whilst I agree with you with most of your points, bear in mind my post does generalize to an extent as it is aimed towards new players and this post is specifically talking about "Tight Players", it's the whole essence of the article.
Tight players will generally play the more premium hands, albeit with some exceptions depending on the situation at hand, but for the most part it can be explained this way.
As expressed in the latter part of the article, I do express that, I myself don't stick to a certain stereotype and ensure to mix it up to remain unpredictable. This goes hand in hand with the concept that it's not always beneficial to think in such a close-minded manner and I would endorse thinking more from a range POV as you become more experienced.
The topics of range, positioning etc. will be covered in other articles, this was meant to provide an overview of the tight play style in particular, without an emphasis on other poker strategies.