Back to Black on Maroon … Mark Rothko's painting has been restored and is on display again at Tate Modern. Photograph: Lefteris Pitarakis/AP  It's a red letter day – or a black on maroon one anyway. Mark Rothko's Black on Maroon, vandalised at Tate Modern in 2012, has at last gone on view again. It was clearly a serious attack, for the restoration has been slow and difficult. Now everyone is happy. Rothko's family praise the Tate restorers for their dedicated work. One of the most powerful modern paintings in Britain has returned to the light. Hooray.  But has the Tate thought at all about why the attack happened, and has it considered for a second – can it bring itself to ask – if the less than conventional atmosphere of Tate Modern as an art museum may encourage a lack of reverence for its art? After all, it's not long since some children were spotted using its Donald Judd as a climbing frame. Is that so surprising when Tate Modern is famous for presenting slides as art?  All of which is of our time but it's not what Rothko himself considered serious art. When he gave a large proportion of his greatest series of paintings to the Tate it was because he was sickened by the idea of these great and worrying visionary masterpieces ending up in the place originally planned for them – a posh New York restaurant. For him, art was an intense thing.  For Rothko, painting was a desperate affair. He sealed this sense of being locked in struggle with art's higher angels when he took his own life. One of the things he got depressed about was the rise of pop artists like Andy Warhol. What – seriously – would he make of Tate Modern?  At the old Tate, the one that is now Tate Britain, his paintings had their own room until the end of the 1990s, as quiet as a chapel. You can still contemplate them mystically at Tate Modern, but never as purely. Like everything else they must fit into this museum's nervously unpredictable displays and banal "juxtapositions" of past and present.  The mood of this museum is the antithesis of everything Rothko stood for. It's noisy, riotous, and pop-cultural. Teens in the toilets, art lovers crying in the corner. Interactive art was being stressed at the museum at the time the Rothko was attacked. Did the idiotic vandal, who claims to be an artist, somehow gain courage from that?  The atmosphere and ethos of Tate Modern incite irreverence towards the art. Are museums really entitled to turn themselves into massive club venues? Or should they be places of silent reverence? What's so very wrong with the museum as a refuge of thought?  There's a case for moving the Rothkos to a quieter place where these great paintings can be seen in a context that Rothko would have wanted and that his art deserves. Perhaps the National Gallery might have them on long-term loan – for he was thinking about Michelangelo when he painted them.  Or perhaps Tate Modern should grow up, and accept that a museum's most important job is to preserve great art and create an atmosphere conducive to enjoying and understanding it. Which by definition is not a place where art vandals feel at home.
Jonathan Jones: A restored Black on Maroon is back in the place where it was vandalised 18 months ago. But is it the atmosphere of this noisy, pop-cultural gallery that incites irreverence towards art?