Why have the West Indies cricket team got so bad?

Talent in T20 doesn't convert into performances in the highest level of cricket - Test Cricket.

However apart from that cliche, there are multiple reasons for the abysmal performance of the West Indian cricket team.

1. Lack of a good leader: One should keep in mind that the West Indian team is a collection of nations across the Caribbean and hence to unite them and play together as a team can be done only when there is a leader who shows that there is something worth fighting for in the sport. Sadly, ever since Clive Lloyd the standard of captains has been steadily on the decline; there has not been a single captain who can garner support from all the Caribbean nations and to gel together as a team, that is critical.
2. End of the nationalist paradigm: The players rose to excellence on the back of a nationalist upsurge back in the early 70s. That nationalist upsurge has now come to an end and thus the nationalism in cricket has as well.
3. A Board which doesn't care about the sport: The West Indies Cricket Board (WICB) is the biggest culprit. The West Indies Cricket Board of Control, which was the predecessor to the WICB, had just one full-time employee in the 1980s. Unsurprisingly, it failed to put in place a structure to build on success. Since then, a regular turnover of administrators, and infighting between the different Caribbean nations has added to its woes. Relations between the WICB and the West Indies Players’ Association have often been appalling. Since 2005, when seven team members missed a Test match against South Africa because of a contractual row, there have been numerous altercations between the players and the board. Last November, the West Indies pulled out halfway through a tour to India following another contractual dispute.
4. Better Money on offer for the players elsewhere: Usually the row between the players and the WICB is about money. So the cricketers find new employers. As Twenty20 leagues have developed around the world—most notably the Indian Premier League (IPL)—so West Indies players have found that they are able to earn far more playing in them than for the national team. Its biggest stars, including Chris Gayle, have regularly missed international cricket to play in the IPL. As the West Indies fields under-strength teams, so many in the Caribbean now prefer to watch American sports on TV instead. Baseball & Basketball are sports that pay them a lot more and also show them a new and better life in the USA. More youngsters target that instead of cricket.
5. Lack of First Class infrastructure: Earlier, West Indies cricket came to maturity with the English counties as the finishing school. With the new visa regulations, it is tough to play in the English County; hence that adds to their systemic decline.

It is known that in all societies there is a tendency for cultural excellence to rise and fall. Over time and generations, what has happened in cricket is just a normal part of nature at work in society.

As a true cricket fan, I am sure that West Indian cricket will bounce back in another 10 years or so. I am only hoping there are other teams that will be up to scratch then!