The issue is clearly a difficult one as has been alluded to elsewhere in the thread. No one here is saying that the man was a saint, or that they agreed with everything he advocated or supported. But he was brutally stabbed to death in his role as an MP, democratically representing his constituents. All that was said about him in a positive sense was that he was a "decent man". No one really went any further than that. Most here will have no knowledge of him personally at all beyond his voting record, a Wikipedia page and the odd bit of news reporting about him.
Firstly, it should be possible to distinguish the personal from the political, although some people will find that hard. My mother is conservative, as are some of her friends, as are some of mine. I still consider them decent people (perhaps not ALL of her friends, but that's not the point...) He was seemingly liked and respected across the political spectrum, and again that's as much as anyone said really. No one was trying to whitewash him as a politician, the focus was correctly on how awful it was for someone to be brutally murdered in these circumstances.
Secondly, if you can't say anything nice about someone, maybe it's best not to say anything at all on the day they were stabbed to death. This doesn't mean your views on the wider issues being discussed here aren't relevant, important, significant etc. It's simply to show the appropriate level of respect and to reflect on what happened today and what it represents, both in relation to our democracy, society as a whole, and to the family of David Amess.