We don't want to see that the new investors come, say that we instamine this coin for 3 months and now reduce to block reward to make advantage for us. That's why we keep the current value of block reward through voting (15.37 TAC) and halving it after 1.5M blocks. So new investors could still have the same advantage to join in.
I don't really see people thinking that, I think you're worrying about being defensive about something which isn't a big issue anyway. There was our pet troll but he was just trolling. The rest of the community haven't been complaining about it, and those people (including me) are going to feel pretty disillusioned after hoping that the inflation would be brought under control.
By the time the block reward halves our investment will be worth about a quarter of what it is now (in percentage terms) and a year is so far into the future in crypto terms that it might as well be forever. I doubt you'd find a single person who invests on the basis that the inlation will decrease by 50% in a year's time. Who would tie their money up for that long while it devalues so much every month.