Well, that was pretty short. In my opinion, it's better to put hardforks on Bitcoin and solve the issues that it may have than to go creating new cryptocurrencies to "substitute" the one that is already on the way to improvement, to become what we really want.
Otherwise, we'll be promoting eternal branching and weakening of each cryptocurrency that we want to support and that will probably end up in many of the concepts dying from weakness in the face of other stronger cryptocurrencies that may not be as good but have been solid since the start.
True I do see merits in hard fork but they lead to less nodes. Don't get me wrong bitcoin will need to do a HF to make the LN even cheaper and faster. However the concept of just HF justs seems sad. Oh we need to scale...let just inc the blocks and sacrifice some nodes . Second with the use of atomic swaps and other tech-bitcoin sidechain will become so easy to use. These sidechains will give the tech of altcoins the price and brand name of bitcoin.