In my mind it all comes down to the difference between an RPG and a board game. An RPG system provides a framework, from which a group of people build a collective experience -- there is no winning or losing, whether or not goals or ambitions are accomplished. The more you make it about a set of rules that delineate what can and cannot be done, the more you lose immersion and the less of an "experience" it becomes. Board games, even cooperative board games, are designed to be won or lost and as such must cleanly lay out hard and fast rules (as much as possible) to achieve this this with any certainty. Board games without rules that cover every little situation are bad. In board games, you find every little way to gain advantage by working within the rules, because that's part of the game. You're actively thinking about working the rules to your advantage. Doing so in D&D is very much opposed to the point of the game. Moreover, of course we know it's completely impossible to cover every situation, and it's not worth trying. So a simple framework is made. To compensate, in D&D the DM has (and has always had) complete control. With a good DM this provides the same certainty that rules provide to board games, and it also provides a kind of tension and uncertainty that heightens the experience of roleplaying, which board games can never hope to achieve.
So much of the complaining about the design philosophy of 5e is from people who either didn't get exactly the game they were hoping for from 5e or would be happier playing board games or video games anyway. I'm of the opinion that there is both a very strong philosophy and overall very high quality design in 5e. I'm extremely happy that 5e was written in a way that empowers the DM and players to "play their own game," since this more than anything else is what makes D&D unique. There are details that could be cleaned up in the books, no doubt. I'm hoping the "living rule set" model works well for dealing with these kinds of issues, since it seems like a very smart and modern paradigm for an rpg ruleset --- learning a variety of lessons from previous editions. Putting off release of the game by a month or a year would not to completely wipe out any such issues, and I'm glad I didn't have to wait to satisfy those people who think that should have been done, because there's way too much excellence in these books.