After a lot of complains by Dota players, Valve gave a hint that it’ll ban a lot of players in various cycles. The next Ranked Season started today and as stated by valve, a lot of players are getting banned. The length of the ban is mostly up to 2038. This means that players cannot play till 19 years, almost two decades. Most of the players are banned due to cheating, account trading, racism and abuse.

Players reaction to the ban wave was a big surprise. Many players complained about the ban, however most of them also praised Valve for their actions and changes. As per reports, the Steam forum and Dota 2 sub-reddit are being flooded with complains by players who are banned till 2038. 
Here is a reddit post by Dota 2 player praising Valve for their changes.

Additionally, Valve has also planned to ban multiple players forupto 1 week on the basis of behavioral score. The numbers associated with weekly bans will be blacklisted, thus there will be limitations to the game. Other changes also included significant decrease in smurf accounts. Valve reports that a bug was fixed which allowed players to play without their phone numbers.

A recent post by Reddit Dota 2 on twitter explained that the ban for 19 years is not temporary. The ban will last permanently and there is a issue with digital storage of time, hence it shows 2038.

Conclusion:
I think it is a positive step taken by valve to revive Dota 2. The Dota 2 community was very toxic lately and these changes will suppress them. Many Dota 2 players on forums are happy with the current decision. Additionally, players are also saying that 2012 Dota 2 is back and they are happier than never before.