Caizer has said he cannot afford to develop both games in tandem. He chose to work on his Happy Summer project because his Patrons are actively paying money in support of its development.
Forgive me if I'm mistaken, but I think you would find it ridiculous to suggest that you start subscribing to his Patreon now in the hope that he will be prepared to immediately switch and commit all development over from Happy Summer to My Lovely Sara.
Yet you seriously advocate that he now switches all development over from HS to MLS in the hope that you and the "many (who) believe this game is much better" will be prepared to immediately join his Patreon and pay money in support of the development of MLS.
What are you talking about? So much of what you said makes no sense at all.
First of all, Caizer's patreon is for Caizer Games, the account he created initially to receive support for MY LOVELY SARA. He only started receiving support for Happy Summer after he decided to "hold" development on MLS. His patrons were paying him money to support development of that project before he switched over, so your first argument is completely contradictory.
Secondly, Caizer was the one who said that he would continue development of MLS if and when his patreon receives more support. Read his patreon post that is still up, as you clearly forgot or didn't understand:
"...hopefully increase this pages support so that when the time comes I can hire someone to help Remaster MLS by porting it over to Ren'py, updating the renders and improving on the gameplay along with adding some new features."
Third of all, whether he decided to switch back to MLS or do both projects at once is irrelevant. The point is, he was developing MLS FIRST, and decided to change his focus to HS, thereby doing the exact thing you seem to find so ridiculous in expecting his patrons to support development of a new game despite having already invested in his other game.
Regardless of how he would decide to distribute his time, Caizer was the one who said he would come back to it. Again, see his patreon post, and read his OWN words:
"I know that it's always terrible to hear when a game is put on hold but I just want it to be perfect. Just please know, I will be coming back to it later down the line."
So I don't know what you're going on about, but you've clearly misunderstood somebody. It's perfectly reasonable for some to be annoyed that Caizer stopped development of this game, and never came back to it, and to wish he returned to it. It's been over 2 years now, so it's pretty clear it's not going to happen. I've played Happy Summer, and it’s a decent, but not as good as MLS IMO.