Why not? Locking public trading before part of or all, depends how it's structured, of the IPO is sold out is actually completely normal. IPO's main purpose is to raise capita for the Co and not to make quick profit for few speculators. Capital is raised for the Co so it can grow and move to next level.
How would you feel after buying S.DICE and consequently being unable to sell the shares for arbitrarily long time, just because some OCD issuer decided "the IPO is not to make quick profit for few speculators"?
First of all, the time is not set AFTER the IPO placement starts but before. It's not something that just pops up out of nowhere and you are suddenly locked in for some arbitrarily long time.
Idea is, that the time limit (or share limit) can be set before and it if it expires, you free to trade. Or if issuer wanted for some reason, the whole issue gets called back and that is it.
If so many people immediately resell the initial round instead of going long, then that is just bad price setting, or the stock is considered too risky for long-term investment, etc. Nothing of that is solved by forbidding to resell during IPO.
We are not talking about years here
If the limit was set for X days or number of shares, you know what you are getting in to before you lock up your coin. If IPO looks so bad, that you can not sit on it for 3 (just as example) weeks, then the problem is somewhere else.
If you are for quick profit, then last thing you want is the huge second and third pile of stock to hover there and limit your possible gains for sure.
This is starting to get off topic...
Moreover, if both the issuer and the exchange know what is gonna happen and won't give a shit (and in case of S.DICE, even MPOE-PR openly advertises this as profit for first-wave investors)... what is the problem then?
This is your guess. My guess is they did not know what is going to happen. Spinning it later to "profit for first-wave investors" was rather weak. What really happened, is that the max capital gain was locked by the price of the second pile of stock. It was not selling as expected by MP. Sure, s.dice guy was lucky, because he had no real need for additional capital to expand or start up a new project.
Actually, where do S.DICE even plans to expand? Are they planning to come up with with a new and exiting product under the same company that will not cannibalize the existing dice game? Or is it just adding more and more virtual servers to serve more and more players? (not really a question for this thread, please ignore)
What is happening now is that every new share, that is sold form this same old IPO keeps watering down the soup. Those shares are not treasury stocks any more. While number of outstanding shares grows and if income remains about the same, suddenly those fabulous dividends to not look so exiting after all. Whats even worst, capital gains are still blocked by the 2 (or is it one now?) huge pile of unsold stock. Share price will not go above it unless those get sold or IPO size is reduced.
Imagine, if they had enough brains and cuts to cancel the rest of the IPO for now and hold the leftover shares for better days. Those shares can sit in the book as TS and bother no one - they do not get divs not can those be used for voting... voting is actually completely pointless in s.dice because IPO represents only 10%, if it's sold out in full.